The conventional tube-like container has been manufactured by stretch blow molding by using a preform of which the drum part is cylindrical. After forming the drum part of the preform into a cylindrical drum part which has thin wall thickness and greater length than the finished product by stretch blow molding, a primary molded product opened at the lower end of the drum part is manufactured by cutting, and the opening at the lower end is closed by flattening and welding the wall of the lower end to make a flattened bottom end.
Consequently, cutting in the secondary working produces numerous chips which are liable to become waste of material. Moreover, even if the chips can be used as recycled material, the cost of recycling is high, so that the cost becomes comparatively higher than that of a packaging container in usual shape.
Furthermore, in the case of closing the lower end opening by welding after filling the container with the contents, the chips and the like may easily be mixed into the contents, so that it is difficult to use such a container as a packaging for foods and the like due to contamination.